Laparoscopic laser-assisted bladder autoaugmentation

Use of an inflatable silicone balloon improves the success rate of bladder autoaugmentation at long-term followup

PURPOSE

Most groups have reported disappointing results with autoaugmentation or detrusor myectomy for low capacity/compliance neuropathic bladders. Failure may be due to an ischemic diverticulum or mucosal shrinkage. We investigated whether a Silimed® silicone balloon placed in the bladder after autoaugmentation could prevent these problems, improving surgical results.

MATERIALS AND METHODS

We compared the results of standard bladder autoaugmentation in 12 children (group 1) with those in 10 (group 2) who underwent the same surgery using a bladder conformer. The conformer was a silicone balloon filled with saline that remained in the bladder for 2 weeks. All patients had a neuropathic bladder with poor capacity and compliance, resulting in urinary leakage between catheterizations. Preoperative and postoperative evaluation included a voiding diary, ultrasound, voiding cystourethrogram and urodynamics.

RESULTS

In group 1 only 1 patient became dry, 4 had little improvement in continence, 4 remained unchanged and 3 became worse. In group 2, 6 patients (60%) become continent without medication, 2 (20%) become continent with oxybutynin and 2 remained unchanged. Bladder capacity and compliance did not change significantly in group 1. However, in group 2 capacity changed from a mean of 140 to 240 ml and mean ± SD compliance increased from 15.6 ± 16.8 to 34.3 ± 22.8 ml/cm H(2)O (p = 0.02).

CONCLUSIONS

The inflatable balloon improved our long-term results of bladder auto-augmentation. A larger series may be necessary to confirm procedure efficacy and safety.

Hand-assisted demucosalized gastrocystoplasty comparing different tissue closure methods

OBJECTIVES

To perform experiments to determine whether a new tissue sealant (SynthaSeal) could be an alternative for suture closure in minimally invasive bladder autoaugmentation gastrocystoplasty using demucosalized stomach. Alternative methods to suture closure for tissue approximation such as laser tissue welding and fibrin glue have been reported.

METHODS

Minimally invasive autoaugmentation gastrocystoplasty with demucosalized stomach was performed on 14 female mongrel dogs. Two dogs were used to refine the technique. The remaining dogs were assigned to a suture group (n = 6) or a SynthaSeal group (n = 6). Anastomoses were performed using either SynthaSeal or suture. The in vivo bladder volumes and pressures of the groups were measured before and after gastrocystoplasty. The animals were studied on day 14. Samples of the anastomotic area were taken to measure the tensile strength and stress. Histologic analysis was conducted to assess tissue healing. The anastomotic time was recorded for each group.

RESULTS

The tensile strength of the anastomoses in the SynthaSeal group was significantly increased (9.99 +/- 1.14 Newtons) compared with the suture group (5.66 +/- 0.97 Newtons) (P <0.05). The breaking stress comparisons and anastomosis times were equivalent between the two groups. The histologic evaluation revealed minor tissue devitalization and a normal inflammatory response in both groups.

CONCLUSIONS

Minimally invasive gastrocystoplasty using demucosalized stomach can be successfully performed with SynthaSeal tissue sealant. This may provide a reliable alternative to suture closure.

Laser-assisted demucosalized gastrocystoplasty with autoaugmentation in a canine model

OBJECTIVES

Laser-assisted autoaugmentation gastrocystoplasty has been performed successfully. Experiments were performed to determine the optimal laser for tissue welding during demucosalized autoaugmentation gastrocystoplasty using both a 1.9-microm diode and a 1.32-microm neodymium:yttrium-aluminum-garnet (Nd:YAG) laser with and without thermal control.

METHODS

Autoaugmentation gastrocystoplasty was performed on 18 female mongrel dogs. Anastomoses were performed by either suture or laser welding with a 50% human albumin solution. A 1.9-microm diode laser was compared with a 1.32-microm Nd:YAG laser with and without thermal control. In vivo canine bladder capacity measurements were performed both before gastrocystoplasty and at euthanasia. The animals were studied on days 4 and 14. Samples of the anastomotic area from each group were taken to measure tensile strength. Histologic samples were assessed for tissue damage.

RESULTS

There was a significant increase in bladder volume in the 4-day group compared with pregastrocystoplasty values. Both the 1.9-microm diode laser and suture control dogs with the 14-day repairs had significantly more tensile strength than their 4-day counterparts. In contrast, no statistical difference was found between the 4 and 14-day 1.32-microm Nd:YAG groups. The suture control group had evidence of minor tissue devitalization at the anastomosis at both 4 and 14 days. The 1.9 and 1.32-microm laser groups both had evidence of tissue devitalization at 4 and 14 days. The 1.32-microm laser group had primarily severe tissue injury. The laser groups at 14 days demonstrated an inflammatory reaction that was localized to the albumin.

CONCLUSIONS

Demucosalized gastrocystoplasty with autoaugmentation can be safely and successfully performed with a 1.9-microm diode laser without significant differences in tensile strength when compared with suture controls. The 1.32-microm Nd:YAG laser can also be successfully used; however, the long-term results appear to be inferior to the 1.9-microm diode laser.

Laparoscopic bladder seromyotomy: laboratory experience

Twelve female microminipigs with normal bladder capacity underwent laparoscopic bladder seromyotomy. Three other female microminipigs were added to the study as controls. Urodynamic studies and cystograms were performed preoperatively and at 2 and 4 months after a laparoscopic bladder seromyotomy. Histologic studies of the treated bladders were performed when the animals were euthanized at 4 months. The operation was completed in all 12 test animals. There was no significant difference in bladder capacity or leak-point pressure between the 12 seromyotomy and the 3 control bladders at any time point. Histologically, over the seromyotomy site, the urothelium remained intact; however, the muscularis was attenuated, and a thin layer of fibrotic tissue replaced the normal serosal covering of the bladder. Laparoscopic bladder seromyotomy can be performed reliably in the porcine animal model. Not surprisingly, no significant changes in bladder capacity or bladder compliance were seen in our study of normal bladders. An animal model of a neuropathic contracted bladder is needed to assess more accurately the physiological impact of laparoscopic seromyotomy.

Bladder autoaugmentation

Autoaugmentation has proved effective in many patients in lowering bladder pressures, increasing bladder capacity, and improving their related symptoms. Patients with sever bladder hyperreflexia, uncontrolled with medications, have also benefited greatly from autoaugmentation procedures. Only patients who failed conventional medical management have undergone autoaugmentation at the authors' institution.